Cellogy has developed a novel technology concept, called PulseTM, for the functional characterization of stem cell-derived cardiomyocytes. Pulse performs automated characterization of beating cardiomyocytes using video microscopy and novel image analysis algorithms, and provides a level of automation and scale otherwise not available. Pulse generates measurements of beating frequency, irregularity, and QT interval based on motion analysis of phase contrast images captured at a fast frame rate. Pulse is the first beating assay designed to be fully compatible with common cell culture practices, completely non-invasive to cells, and cost- effective, making it ideal for large-scale cardiovascular drug development and cardiotoxicity testing. In addition, Pulse accommodates any type of cell plating by automatically recognizing distinct beating regions, enabling new types of high-throughput single-cell studies. Cardiac safety is an important problem facing the pharmaceutical industry, and accounts for nearly 40% of the withdrawal of FDA-approved drugs from the market. The concerns over cardiac safety are further complicated by the extremely high costs of new drug development and the low success rates of late-stage clinical trials. There is therefore a significant need for better tools to predict cardiotoxicity during the preclinical stages of drug development. Such tools would have a significant impact on human health and the U.S. economy by developing safer drugs and reducing costs related to drug failures. Patch clamp assays are the current standard reference for high-precision electrical measurements of single cardiomyocytes. However, they require manual setup by a trained expert. Such assays are inherently a low-throughput technology that will not scale to meet the demand of large-scale drug testing. One alternative, imaging of calcium signaling, is useful as a reference, but limited by potential interactions with other compounds. We believe that a contact-free, label-free imaging technique is not only a viable alternative, but also a technology that will enable cost effective high-throughput analysis in a completely automated fashion. Such automated and non-invasive assays can be used more routinely for drug development, and ultimately for patient specific studies. Over the past year, we have successfully completed the initial development phase and demonstrated the feasibility of our Pulse technology platform. In this Direct-to-Phase II SBIR proposal, we seek funding to support and accelerate the development of the Pulse product. Our goal is to continue to innovate and optimize the Pulse product so it may become the standard 'go-to' assay for cardiomyocyte-based drug screening and toxicity testing.